The "X Factor" judge showed off seriously lighter (and straighter) locks at the 2013 National Children's Mental Health Awareness Day in Washington, D.C., on Tuesday -- the same day that she began streaming her latest album, "Demi," online ahead of its May 14 release.

Lovato, 20, was in D.C. to be honored with an advocacy award from the Substance Abuse and Mental Health Services Administration, for speaking out publicly about her struggles with bipolar disorder, as well as drugs and alcohol.

While she's rightly earning raves for her good work, Lovato also should be recognized for her tresses, which she changes about as often as Simon Cowell makes a catty comment to a contestant on their Fox reality show.

In the past year, she's dyed her hair dark red, rich brown, and blond, and has added streaks of pink, green, and blue. And yet, somehow, despite the frequent color treatments, her hair always looks glossy and gorgeous.

Lovato revealed to omg! in October, when she'd also just gone blond, that her secret to keeping her strands strong is … a lot of luck.

"I have no idea [how it stays healthy]," she said with a laugh. "My hair is really soft and really long right now and I just went even blonder, so I have no clue! I guess it's the salon that I go to is really incredible -- Nine Zero One in Los Angeles -- and they know how to lighten hair without damaging it. I also have some pretty awesome deep conditioner, and I try not to wash my hair as much as possible … maybe every two or three days."